PARIS (AFP) ― Most international bribes are paid by large firms with the knowledge of senior management, the OECD said Tuesday, after analyzing hundreds of prosecuted cases spanning a quarter century and worth a total of $5.9 billion.

“Corporate leadership is involved, or at least aware, of the practice of foreign bribery in most cases, rebutting perceptions of bribery as an act of rogue employees,” the club of wealthy nations said in a report.

The report analyses 427 cases involving the 41 signatories to the OECD Anti-Bribery Convention since it took effect in 1999.

“Given the complexity and concealed nature of corrupt transactions, this is without doubt the mere tip of the iceberg,” the report said.

Nearly half of the bribes paid to foreign public officials originated in developed countries, and 21 of the cases involved heads of state or government ministers receiving bribes, the study found.

The four sectors most affected are mining, construction, transportation and storage, and information and communication.

Well over half ― 57 percent ― of the bribes averaging $13.8 million each were paid to win public procurement contracts, and three-quarters involved payment through intermediaries, the OECD said.

“Bribes were promised, offered or given most frequently to employees of state-owned enterprises (27 percent), followed by customs officials (11 percent), health officials (7 percent) and defense officials (6 percent),” the report said.

Eighty individuals served jail time after being convicted of foreign bribery, while 261 individuals and companies paid fines, it said.

Sixty-nine percent of the cases were settled with sanctions, it added.

“One in three cases came to the attention of authorities through self-reporting by defendant companies or individuals,” it said, while whistleblowers accounted for just 2 percent.

“Companies that self-reported became aware of the foreign bribery in their international operations primarily through internal audits,” the report said.

Media coverage led to 5 percent of the cases. Currently, 390 probes are underway in 24 of the convention signatories, it added.

The Organization for Economic Cooperation and Development provides economic analysis and advice to its 34 industrialized members.

“Corruption undermines growth and development,” OECD Secretary-General Angel Gurria said in a statement, adding: “The corrupt must be brought to justice. The prevention of business crime should be at the center of corporate government (and) public procurement needs to become synonymous with integrity, transparency and accountability.”

The group urged governments worldwide to “strengthen sanctions, make settlements public and reinforce protection of whistleblowers as part of greater efforts to tackle bribery and corruption.”